One of the preferred methods of surgical stapling is surgical staplers activated by pneumatic feed lines. These surgical staplers provide repeatable ascertainable levels of stapling force so that all users are able to actuate and perform surgical stapling procedures, in especially hard to reach or awkward positions where manual actuation may be difficult, or even impossible.
Nonetheless, previous pneumatic stapling devices have shown certain drawbacks which have proved difficult to correct. Among these are the lack of remote or automatic pin placement. The retaining pin is utilized to contain tissue and provide alignment between the stapling cartridge and the anvil during tissue compression. On pneumatic stapling devices it has proven difficult to create remote pin placement through a pneumatic system. Yet, current retaining pins have been difficult to use, as their clearance may interfere with tight spaces in the body cavity.
Similarly, because there are different tissue thicknesses, it is desirable to provide a pneumatic stapler which has adjustable staple height mechanisms. In this way, each stapler is capable of accomodating varying tissue thicknesses.
Third, pneumatic stapling devices have not been able to provide a system whereby the stapling head has a controlled closure of the head onto the tissue. In previous devices, during tissue compression, the pneumatic pressurization of any compression bladder had the potential for rapid closure of the head without careful control of the supply pressure. In some instances, even careful control could not prevent rapid closure.
Because these staplers are desired to be reloadable, it is desirable to create a system whereby depressurization of the instrument is accurate and repeatable and affords the user the capability of removing a stapling cartridge and replacing it with a fresh cartridge for continued tissue stapling purposes.
Particularly important with limited access applications is the size of the anvil. Because the staples must be emplaced onto an anvil for closure, there must be a mechanism behind the tissue to be closed. The smaller the anvil head can be made, the more versatile the stapler becomes.